Iron Pyrite- Uses & Applications
If you were to see Pyrite (Iron Pyrite is one form), you’d be forgiven for thinking it’s a precious metal. In fact, it is mistaken for one ...more on that later. But Pyrites is special in terms of the applications it can cover.
For example, those brown bottles you might be familiar with drinking out of aren’t brown through some kind of artificial colour. They contain Pyrites as a colouring agent.
But first let’s look at what Pyrite is and then we’ll go on to explore its applications, benefits and more.
What is Pyrite? Pyrite is a golden yellow mineral with a shiny metallic lustre. The chemical composition is iron sulfide (FeS2). Pyrite is the most common sulphide mineral, it forms at both high and low temperatures and usually occurs in small quantities within igneous, metamorphic, and sedimentary rocks globally.
Pyrite is actually really common, so common in fact, that geologists generally consider it to be a ubiquitous mineral. With a lot of it around, that means it can be mined and used for many applications, more on that later.
Why Is It Called Pyrite?
The Greeks used Pyrite for lighting fires because it creates sparks when struck against a solid material. Therefore, it was named after the Greek word ‘Pyr’ meaning ‘Fire’. This concept was carried on to some flintlock based arms such as muskets - to generate the powder spark.
Here are the physical properties of Pyrites…
|Physical Properties of Pyrite|
|Colour:||Brass yellow - often tarnished to dull brass|
|Streak:||Greenish black to brownish black|
|Cleavage:||Breaks with a conchoidal fracture|
|Mohs Hardness:||6 to 6.5|
|Specific Gravity:||4.9 to 5.2|
|Diagnostic Properties:||Colour, hardness, brittle, greenish black streak, specific gravity|
|Chemical Composition:||Iron Sulfide, FeS2|
|Uses:||Ore of gold|
There’s a famous nickname for Pyrites of ‘Fools Gold’. This is because of the deceptive gold colour of the mineral and metallic appearance and lustre which has fooled so many into thinking it must really be gold. But, it often could be. The two minerals Pyrite and Gold do often form together in some deposit layers, so in fact, pyrite can often be mined for its Gold deposits. The most obvious way to tell the difference is that Gold is softer than Pyrite - which tends to be more brittle.
Uses of Pyrite
Pyrite is composed of both iron and sulfur; hence the name iron pyrites, although it is not particularly mined for either of these substances in the modern age. So what uses does Pyrites have? Well here’s the definitive list, then we’ll go on to discuss the benefits.
Pyrite as a Gold Carrying Ore
As mentioned earlier, gold is often found within Pyrite as they tend to form together in the same rock types, in similar conditions. So in some deposits, small amounts of gold can occur as inclusions and substitutions within pyrite itself.
So much so, that some pyrites can contain around 0.25% or more by weight. The small fraction is offset by the value of the included gold, so it’s worth mining for that reason. While it’s not a guaranteed revenue, if does efficiently enough it can be profitable.
Sulphur and Sulphuric Acid
Not so much in the modern era as mentioned previously, but once Pyrites were mined for their source of Sulphur. Sulphur production now mostly comes as a byproduct of oil and gas drilling so much so, that we at African Pegmatites only deal with small quantities of this material of up to 100mt per month - and also not as a raw ore.
As a gemstone Pyrites can be fashioned into all manner of jewellery, but mainly in the form of faceted beads. Not as popular now, but in the mid-to-late 1800s it was highly popular in the United States and Europe. However, it does have a tendency to tarnish when in daily use.
Amber Coloured Glass
By far the most common use for Pyrites in the modern age, and one that we specialize in at African Pegmatite is in the processing of Pyrite for use in amber coloured glass. These are the yellow - almost gold colored to light brown coloured glassware you might find in the consumer or berage market.
Pyrite is mixed with other glass elements to produce this golden yellow-brown appearance. This colouring is for a reason, it has a number of benefits: -
Reduces UV Penetration
Amber glass bottles are excellent at providing UV protection for their contents. So if you want to make sure your beer doesn’t go ‘off’ then this is because UV light is not able to alter the chemical makeup of the neer inside. So, amber glass prevents products from spoiling.
Protects Against Blue Light
Blue light has both positive and negative influences. However, for the contents of amber glass, the primary focus is on the negative effect on food. In particular, the interaction food has with bacteria.
Essentially the photochemical effect of blue light means it can promote the growth of bacteria. Using amber glass helps prevent this growth. When considering blue bottles, it’s worth noting that only amber bottles can prevent blue light.
There are both positive and negative sides to blue light, but the primary concern with any light is the photochemical effect it will have on food and bacteria interacting with the food. If you are weighing the light-blocking protection provided by cobalt blue bottles and amber glass bottles, then only amber glass can protect from blue light.
A Safer Alternative to Other Materials
Like many other glass related products, amber glass can reduce the risk of toxic chemicals leaking into the container contents (known as Leeching) Plastic and other materials are less safe than Amber glass in this regard.
Due to its tough but abrasive nature, iron pyrites is used in the manufacture of vehicle and machinery brake pads. Although brake pads wear down, Pyrite enables longer life of the pads themselves. This is achieved by grinding down the Pyrite into particles and binding them with other elements to form the required brake pad shape.
This is also why residual dust from brake pads can often have a shiny gold looking sheen to it, if you see this, then it’s likely to be Pyrite particles.
The Manufacturing of Cast Iron
The level of residual sulphur is reduced when Pyrites is melted in foundries, primarily due to the use of scrap steel and low sulphur content. It has been determined that melting does not respond easily to inoculants if the sulphur level is less than 0.04%. Therefore, it is necessary to raise the sulphur content using Ferro Sulphur to maintain the level in a range
Up until recent times, Pyrite was used as a mineral detector in radio receivers ...and is still used by crystal radio hobbyists to this day as it’s the most sensitive material detector they can depend upon for performance. Commercially, this use of Pyrite fell out of use when Vacuum Tubes became a more modern reliable method.
Photovoltaic (Solar) Panels
More recent efforts are working toward thin-film solar cells made entirely of pyrite. When used along with Copper Sulfide, Pyrite could be a low-cost, non-toxic and abundant material as an alternative for the manufacture of solar panels. In fact, researchers are working on a completely Pyrite manufactured Photovoltaic panel of thin-film cells as a revolutionary upgrade to Solar Panels.
Much like brake pads, when Pyrite particles are bound together with other elements such as iron this again forms a tough but abrasive texture. This abrasive surface is ideal as an ‘Active Filler’ for use with grinding wheels and other grinding type applications such as hand grinders. Other materials in the mix, as well as Pyrite, include potassium sulfate and an alkali haloferrate.
You might see some grinding wheels have a brassy glitter look to them. Sometimes Pyrite content can be as much as 80%, so the more glittering the wheel, the more Pyrite is present.
How to Identify Pyrite
Pyrite has a unique look about it. It is angular, almost cuboid clusters in appearance, or octahedrons. It has a shiny brassy sheen, or lustre to it. It is hard and brittle and often has black streaks running through it.
The only common mineral that has properties similar to pyrite is marcasite, a dimorph of pyrite with the same chemical composition but an orthorhombic crystal structure. Marcasite does not have the same brassy yellow color of pyrite. Instead it is a pale brass color, sometimes with a slight tint of green. Marcasite is more brittle than pyrite and also has a slightly lower specific gravity at 4.8.
Where Can I Find Pyrites?
Although it can be fairly easy to identify, Pyrites, however, is not so easy to find. You’re unlikely to stumble across it on your morning stroll. And if you’re thinking that Iron Pyrites is magnetic then, yes it is, but only slightly. It depends largely on the iron ore content of the Pyrite but it will be weak in magnetic strength so it’s unlikely to ‘stick’ to a magnet.
Pyrite tends to be abundant within geothermal mineral deposits and among coal beds. It is mined in Carbonate Rock and vein deposits. Italy and China are the largest exporters of Pyrites, but it is also found in large quantities on the borders of Wisconsin, Minnesota, and Iowa.
We hope this has given you a good overview of Pyrites, it’s uses and benefits and a few clues as to what it looks like and where it occurs. For your mineral mining needs, you can contact us here at African Pegmatite for some specialist assistance on your needs, quantities and your overall project. Get in touch and we’ll be happy to help.